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HARMONIC MEROMORPHIC STARLIKE FUNCTIONS
Jahangiri, Jay, M. Korean Mathematical Society 2000 대한수학회보 Vol.37 No.2
We give sufficient coefficient conditions for a class of meromorphic univalent harmonic functions that are starlike of some order. Furthermore, it is shown that these conditions are also necessary when the coefficients of the analytic part of the function are positive and the coefficients of the co-analytic part of the function are negative. Extreme points, convolution and convex combination conditions for these classes are also determined. Fianlly, comparable results are given for the convex analogue.
MEROMOR0PHIC UNIVALENT HARMONIC FUNCTIONS WITH NEGATIVE COEFFICIENTS
Jahangiri, Jay M.,Silverman, Herb Korean Mathematical Society 1999 대한수학회보 Vol.36 No.4
The purpose of this paper is to give sufficient coefficient conditions for a class of univalent harmonic functions that map each $$\mid$z$\mid$$ = r >1 onto a curve that bounds a domain that is starlike with respect to origin. Furthermore, it is shown that these conditions are also necessary when the coefficients are negative. Extreme points for these classes are also determined. Finally, comparable results are given for the convex analgo.
A novel selective H2S sensor using dodecylamine and ethylenediamine functionalized graphene oxide
M. Malek Alaie,M. Jahangiri,A.M. Rashidi,A. Haghighi Asl,N. Izadi 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.29 No.-
Dodecylamine (DDA) and ethylenediamine (EDA) functionalized graphene oxide (GO) nanosensorswere synthesized by amidation methods and characterized by X-ray photoelectron spectroscopy (XPS),Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM). The resultsshowed that compared to pristine GO-based sensor, the DDA-GO and EDA-GO chemiresistors have asignificant response to hydrogen sulfide (H2S) down to 50 ppm at room temperature. Furthermore,operating temperature effects, H2S concentration and GO suspension concentration on sensor responseare also investigated. Functionalized graphene oxide chemiresistors offer advantages such asremarkable potential for mass production due to their ease of manufacturing, significant selectivityand performance.
INCLUSION RELATIONS FOR k-UNIFORMLY STARLIKE AND RELATED FUNCTIONS UNDER CERTAIN INTEGRAL OPERATORS
AGHALARY RASOUL,JAHANGIRI JAY M. Korean Mathematical Society 2005 대한수학회보 Vol.42 No.3
Inclusion relations under certain integral operators are proved for k-uniformly starlike functions. These results are also extended to k-uniformly convex, close-to-convex, and quasi-convex functions
An Integrated Approach to Teaching and Learning College Mathematics
Ahuja, Om P,Jahangiri, Jay M 한국수학교육학회 2003 수학교육연구 Vol.7 No.1
The key features of our integrated approaching and learning college mathematics include interactive and discussion-based teaching, small group work, computer as a tool, problem solving approach, open approach, mathematics in context, emphasis on mathematical thinking and creativity, and writing/communicating about mathematics. In this paper we report a few examples to illustrate the type of problems we use in our integrated approach.
On a Linear Combination of Classes of Multivalently Harmonic Functions
OM P. AHUJA,JAY M. JAHANGIRI 경북대학교 자연과학대학 수학과 2002 Kyungpook mathematical journal Vol.42 No.1
New classes of multivalent harmonic functions are introduced. We give sufficient coefficient conditions for these classes. These coefficient conditions are shown to be also necessary if certain restrictions are imposed on the coefficients of these harmonic functions. Furthermore, we determine a representation theorem, inclusion relations, and distortion bounds for these functions.
On a Class of Univalent Functions Defined by Ruscheweyh Derivatives
SHAMS, S.,KULKARNI, S.R.,JAHANGIRI, JAY M. Department of Mathematics 2003 Kyungpook mathematical journal Vol.43 No.4
A new class of univalent functions is defined by making use of the Ruscheweyh derivatives. We provide necessary and sufficient coefficient conditions, extreme points, integral representations, distortion bounds, and radius of starlikeness and convexity for this class.
Gharibi, Vahid,Cousins, Rosanna,Mokarami, Hamidreza,Jahangiri, Mehdi,Keshavarz, Mohammad A.,Shirmohammadi-Bahadoran, Mohammad M. Occupational Safety and Health Research Institute 2022 Safety and health at work Vol.13 No.3
Background: Respiratory masks can provide healthcare workers with protection from biological hazards when they have good performance. There is a direct relationship between the visual specifications of a mask and its efficacy; thus, the aim of this study was to develop tools for qualitative assessment of the performance of masks used by healthcare workers. Methods: A mixed-methods design was used to develop a qualitative assessment tool for medical face masks (MFM) and particle filtering half masks (PFHM). The development of domains and items was undertaken using observation and interviews, the opinions of an expert panel, and a review of texts and international standards. The second phase evaluated the psychometric properties of tools. Finally, the validated Mask Qualitative Assessment Tools (MQAT) were used to assess six samples from 10 brands of the two types of masks. Results: MQAT-MFM and MQAT-PHFM shared 42 items across seven domains: "cleanliness," "design," "marking, labeling and packaging," "mask layers," "mask strap," "materials and construction," and "nose clip." MQAT-MFM included one additional item. MQAT-PHFM included another nine items associated with an eighth "Practical Performance" domain, and the valve version had another additional "Exhalation Valve" domain and six items. The evaluation indicated 80% compliance for MFM and 71% compliance for PFHM. "Marking, labeling and packaging" and "Layers" were associated with the least compliance in both types of masks and should be checked carefully for defining mask quality. Conclusion: MQAT can be used for immediate screening and initial assessment of MFM and PHFM through appearance, simple tools, and visual inspection.